Today, Doodles are an opportunity for Google to express its values (like technology, innovation, and quirkiness) in a fun, visual way, Germick explains. That rationale has led to creating thousands of incredibly diverse Doodles over the years, like celebrating Sally Ride, honoring the man who invented the Moog Synthesizer, and making a statement about equality right before the Sochi Olympics.

The effort has expanded from a one-person operation to a team of about a dozen artists, a handful of engineers, and a couple of program managers.

There's also a much more organized process where Doodlers plan out their artwork for the year at long brainstorming sessions, making sure that they're representing a diverse array of people and events. Although the team works out of Google's Mountain View headquarters, they create country and region-specific artwork too, meaning, for example, that an artist may get matched with a Slovenian Googler to jointly come up with the perfect way to celebrate a nationally beloved poet.

Google has also become much more ambitious about what it does with the Doodles, too. The company often moves beyond the static illustration format to create interactive experiences or games. A few years ago, to celebrate father of electronic music Robert Moog, the team built a mini-synthesizer that homepage visitors could "play," allowing them to record and share their own songs.

The Doodle team. Google

When he talked to Business Insider, Germick and his team were just preparing to launch a Doodle for Wilbur Scoville, who created the scale to measure the spiciness of peppers.

"We love knowledge that enriches our lives in some way," he says. "For the Scoville Doodle, we were inspired by an individual's passion to try to categorize something that wasn't categorized. In some ways — in the grand scheme of the universe — it wasn't the biggest thing, but it's beautiful that he was able to put order to something that wasn't ordered."

Germick says that the ideal Doodle not only speaks to Google's values, but is educational, immersive, and emotionally resonant for people in some way.

"Even if it's a one-second smile, spread that across a billion users and that's a billion seconds of smiling," he says.